A more thorough explanation:

causa causae est causa causati

In torts, this principle means that the cause of a cause is also considered as the cause of the effect. It is not just the immediate cause that is responsible for the outcome, but also the underlying cause that led to it.

For example, if a person is injured in a car accident caused by a faulty brake system, the manufacturer of the brake system can be held responsible for the injury, even though they were not directly involved in the accident. This is because the faulty brake system was the cause of the accident, and therefore the cause of the person's injury.

Another example is if a person slips and falls on a wet floor in a grocery store. The immediate cause of the fall was the wet floor, but the underlying cause may have been a failure to properly maintain the floor or put up warning signs. In this case, the store could be held responsible for the person's injuries because they were the cause of the cause.